We currently support Let’s Encrypt and ZeroSSL ACME certificate authorities. You can choose either one of those to create a SSL/TLS certificate for your deployed application.
Note that when using ZeroSSL you must have an account registered with this authority. You will need to provide your account’s email address when issuing free certificates with this provider.
Certificate creation is fully automated via Serverfluent. Follow the instructions on App > Certificates page to create new certificates and manage existing ones.